1. Of, relating to, or characterized by an increased osmotic pressure (typically higher than the physiological level).
2. A condition in which the total amount of solutes (both permeable and impermeable) in a solution is greater than that of another solution.
For instance: In kidneys, the tubular fluid is:
– iso-osmotic (to plasma) when it is at the beginning of the loop of henle
– hyperosmotic (to plasma) when it is at the tip of the loop
– hypo-osmotic (to plasma) when it leaves the loop
Word origin: G. hypo: under, below + osmotic: relating to osmosis.
Related forms: hyperosmotically (adverb), hyperosmosis (noun).
Related phrases: hyperosmotic solution.
Compare: hypoosmotic, isoosmotic.
See also: tonicity, osmosis, osmotic pressure, diffusion, plasma membrane.